CVE-2026-77117
Publication date 27 August 2026
Last updated 24 September 2026
Ubuntu priority
Description
Converting crafted SHIFT_JISX0213 input to UCS-4 or the internal wide character encoding, for example with iconv, in the GNU C Library version 2.3 to 2.44 may result in the converter making no progress, causing the calling application to hang. Some SHIFT_JISX0213 sequences decode to two code points. If the output buffer has room for only the first one, the converter stores the second in the conversion state and returns E2BIG, but it never clears that pending character after emitting it on the next call. The converter then keeps emitting the pending character without consuming further input, so an application that retries the conversion loops forever. The input must be attacker controlled and the application must convert it with an output buffer small enough to split the two code points. Only the SHIFT_JISX0213 character set is affected, which is not commonly used. The related defect in the EUC_JISX0213 converter is tracked separately as CVE-2026-80489.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| glibc | 26.04 LTS resolute |
Fixed 2.43-2ubuntu2.4
|
| 24.04 LTS noble |
Fixed 2.39-0ubuntu8.9
|
|
| 22.04 LTS jammy |
Fixed 2.35-0ubuntu3.15
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
|
| eglibc | 26.04 LTS resolute | Not in release |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 14.04 LTS trusty |
Needs evaluation
|
Patch details
Severity score breakdown
CVSS version: CVSS v3.0
Base score
5.9 · Medium
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8737-1
- GNU C Library vulnerabilities
- 8 September 2026
- USN-8737-2
- GNU C Library vulnerabilities
- 10 September 2026